Environmental Exposures and Neurotoxicology Core (Core C) Director, C Sioutas, Co-Directors: JC Chen and H Forman Abstract The Environmental Exposures and Neurotoxicology Core C, directed by C. Sioutas, includes three supporting subcores to serve the proposed scientific projects, through the provision of the residence-specific exposure estimates in populations, standardization of the inhalation exposure experiments in animal models, and analyses of the neurotoxic responses to traffic-related air pollution (TRAP). SubCore C1, Environmental Data Support (coDir: JC Chen) provides Projects 1 and 2 with individual-level, location-specific estimates of long- term TRAP exposure, using state-of-the-art spatio-temporal modeling approaches harmonized across two human population-based cohorts. Subcore C2, Collection of TRAP-nPM (Dir: C.Sioutas) supplies experimental Projects 3 and 4 with well-characterized TRAP inhalation exposure atmospheres. TRAP are sampled near urban sites impacted by traffic emissions. SubCore C3, Brain Cell Responses to TRAP-PM (coDir: H. Forman) (i) tests individual batches of collected nPM using THP-1 cells for cytokine expression; and (ii) Western blot assay of brain protein changes to in vivo nPM exposure for Projects 3 & 4.